Conveying assistance device

Abstract

To provide a transport assist device that can be driven by the force applied by the transporter at the initial stage, thus eliminating the need for an operating unit, offering ease of use, preventing incorrect movement, and achieving low cost through a simple configuration. [Solution] According to the present invention, the transport assist device 1 can be driven by determining the force applied by the transporter at the start of movement, thus eliminating the need for an operating unit and providing good usability. In addition, since the power to the motor 32, which is the drive source, is turned on by the manual operation of lowering the pedal 21, it is possible to prevent incorrect movement even if there is a malfunction in the control unit or other error. Furthermore, since the wheels 3 that constitute the drive unit 2 are arranged one or more in a rotatable state with a common rotation shaft 31, it has a simple configuration unlike Mecanum wheels and the like, which require the presence of multiple rotation shafts 31 and multiple wheels 3, resulting in a low-cost transport assist device 1.

Description

Technical Field

[0001] The present invention relates to a conveyance assist device. More specifically, the present invention relates to a conveyance assist device for assisting (assisting) the conveyance of an object to be conveyed such as a stretcher.

Background Art

[0002] Generally, when moving an object to be conveyed such as a stretcher or a mobile bed with a patient lying on it in a facility such as a hospital, a plurality of nurses support it by hand in front of and behind the stretcher and push it to convey it to another place. On the other hand, since a stretcher or the like with a patient lying on it has a considerable weight, the burden on the nurses is extremely large. Also, since a stretcher or the like with a patient lying on it is heavy, it cannot be moved by a single nurse in this state, and it was necessary to wait until other nurses arrived during the movement.

[0003] In order to improve such problems, in recent years, a self-propelled conveyance device (self-propelled nursing bed) for self-propelling an object to be conveyed such as a stretcher has been developed (for example, see Patent Document 1, etc.). Such a self-propelled conveyance device includes drive wheels driven by a motor at the lower part of an object to be conveyed such as a stretcher, and a configuration is adopted in which an operator such as a nurse operates an operation unit, and the drive wheels are driven by the motor to move the stretcher or the like.

[0004] On the other hand, the conveyance device as shown in Patent Document 1 described above has a problem that the structure becomes complicated because the stretcher and the drive unit are integrated from the beginning, and in addition, the entire device becomes extremely expensive. Therefore, there has been a demand for providing a conveyance assist device that can be retrofitted with a drive unit or the like to an existing stretcher or the like without a drive unit.

[0005] In response to these demands, transport assistance devices (transportation devices) have been provided that can be retrofitted with drive units and the like to existing stretchers (see, for example, Patent Document 2). Such devices include a Mecanum wheel as a drive unit, an operating unit attached to one end of the object to be transported, such as a bed, in the longitudinal direction (straight direction), and a control unit (controller) that electrically connects and controls the operating unit and the drive unit. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 6-50631 [Patent Document 2] Japanese Patent Publication No. 2024-135278 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0007] On the other hand, if an operating unit is required for the device, the transporter (user) will have to constantly check the operating unit while transporting the object, which makes it inconvenient to use and also leads to problems such as neglecting to properly support the object being transported with the hands of the operator.

[0008] Furthermore, when Mecanum wheels or similar systems, which require multiple rotating shafts and multiple wheels as the drive unit, are installed, they can handle a variety of driving movements such as turning, but the complex configuration often results in high costs. In addition, since the power is always on when the system is in operation, there is a risk of accidental movement if there is a malfunction in the control unit or other error. Therefore, there has been a demand for a transport assistance device that can prevent accidental movement as much as possible.

[0009] The object of the present invention has been made in view of the above-mentioned problems, and is to provide a transport assistance device that can be attached separately to an object to be transported, such as a stretcher, to assist in the transport of such object, and which can be driven by the force applied by the transporter at the start of movement, thus not requiring an operating unit and being easy to use, preventing incorrect movement, and being low cost due to its simple configuration. [Means for solving the problem]

[0010] To solve the aforementioned problems, the transport assistance device according to the present invention is: A transport assist device attached to a transport object equipped with multiple driven wheels, for assisting the movement of said transport object, A wheel is a system in which one or more wheels are arranged in a line, rotatable, with a common axis of rotation. A motor is connected to the wheel with a common rotating shaft, and is driven by the rotation of the rotating shaft when an electric current flows through it. A pedal that lowers the wheel to bring it into contact with the transport surface, It comprises a drive unit for being attached to the object to be transported, A rotation sensor for detecting the rotation state of the wheel, The system comprises a control unit for controlling the drive of the motor, By lowering the pedal, the motor is powered on. The control unit is characterized by determining whether or not to supply current to drive the motor based on a signal communicated from the rotation sensor.

[0011] The transport assist device according to the present invention, as described above, comprises a link mechanism including a plurality of link members that acts as a mechanism for raising and lowering the wheel in conjunction with the up and down movement of the pedal, and a position sensor for detecting the position of the wheel, wherein the motor is powered on when the position sensor detects that the pedal has been lowered and the wheel has been lowered to a preset position.

[0012] The transport assist device according to the present invention is characterized in that the wheel is pivotably mounted to the drive unit together with a member to which the rotation axis of the wheel is attached.

[0013] The transport assist device according to the present invention is characterized in that, in the present invention described above, the up and down movement of the pedal is linked to the up and down movement of the member to which the wheel's rotation axis is attached or the member to which the member is attached, and the position sensor detects the position of the member to which the wheel's rotation axis is attached or the member to which the member is attached by simulating it as the position of the wheel.

[0014] The transport assistance device according to the present invention is characterized in that, in the present invention described above, the control unit determines whether to supply current to drive the motor if the signal from the rotation sensor is above a preset threshold.

[0015] The transport assist device according to the present invention further includes a tilt sensor for detecting the inclination state of the transport surface on which the transport object moves, and the control unit determines, based on the signal from the tilt sensor, that if the signal from the tilt sensor indicates that the transport surface is uphill and is greater than or equal to a preset tilt angle θ1 (θ1>0), then it will supply the motor with a current that is greater than the current supplied when the tilt angle is greater than or equal to the threshold.

[0016] The transport assist device according to the present invention is characterized in that, based on the signal from the tilt sensor, the control unit determines that if the signal from the tilt sensor indicates that the transport surface is on a downhill slope and the tilt angle θ2 (θ2 < 0) is less than or equal to a preset angle, the regenerative brake provided by the motor is activated so that the wheel rotates in the opposite direction to the direction of travel.

[0017] The transport assist device according to the present invention is characterized in that, as described above, the wheel comprises 1 to 3 units.

[0018] The transport assistance device according to the present invention, in the above-described present invention, further includes a load sensor that detects the weight loaded on the object to be transported, the load sensor is a pressure-sensitive conductive member, and the control unit determines, based on the signal from the load sensor, to cause a current having an amount of current corresponding to the loaded weight to flow through the motor.

[0019] The transport assistance device according to the present invention, in the above-described present invention, the object to be transported is a stretcher, and the drive unit is attached to the lower part of the stretcher.

Effects of the Invention

[0020] The transport assistance device according to the present invention can determine and drive the force applied by the transporter at the start-up under the control of the control unit, so it does not require an operation unit and has good usability. In addition, since the power of the motor of the drive source is turned on by manually operating a pedal to lower the wheel to the transport surface, even if there is a malfunction in the control unit or an incorrect operation occurs, incorrect traveling and the like can be prevented. Further, since the wheels constituting the drive unit share a single rotation axis and one or a plurality of wheels are arranged side by side in a rotatable state, unlike a mecanum wheel or the like that requires a plurality of rotation axes and a plurality of wheels, it has a simple configuration and thus becomes a low-cost transport assistance device.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view showing a state where the transport assistance device is attached to a stretcher as an object to be transported. [Figure 2] It is a front view of FIG. 1. [Figure 3] It is a front view of FIG. 1. [Figure 4] It is a perspective view showing one aspect of the drive unit. [Figure 5] It is a side view showing one aspect of the drive unit. [Figure 6] It is a side view showing one aspect of the drive unit. [Figure 7] It is a rear view showing one aspect of the drive unit. [Figure 8] This is a rear view showing one aspect of the drive unit. [Figure 9] Diagram showing the internal structure of the pedal stand, including the linkage mechanism. [Figure 10] Diagram showing the internal structure of the pedal stand, including the linkage mechanism. [Figure 11] This is a block diagram showing the configuration including the control unit of the transport assistance device. [Figure 12] This is a perspective view showing one aspect of a control unit. [Figure 13] This is a front view showing one aspect of the control unit. [Figure 14] This diagram shows a flowchart illustrating an example of the processing performed by the control unit. [Figure 15] This diagram shows a flowchart illustrating an example of the processing performed by the control unit. [Figure 16] This diagram shows a flowchart illustrating an example of the processing performed by the control unit. [Modes for carrying out the invention]

[0022] (I) Configuration of the transport assistance device 1: Hereinafter, an embodiment of the transport assistance device 1 according to the present invention will be described with reference to the drawings.

[0023] Figure 1 is a perspective view showing the transport assist device 1 attached to the stretcher 9, which is the object to be transported 9. Figures 2 and 3 are front views of Figure 1 (Figure 2 shows the state where the pedal 21 is not pressed and the wheel 3 is raised, and Figure 3 shows the state where the pedal 21 is pressed and the wheel 3 is lowered; both are magnified views of the area around the drive unit 2).

[0024] The transport assistance device 1 according to the present invention is attached to the underside of an object to be transported 9, such as a stretcher 9, a mobile bed, a trolley, or a transport cart, and is capable of assisting the movement of the object to be transported 9. Specifically, when the transporter (user) applies an external force to the object to be transported 9 by pushing it in the direction of travel (forward, see the arrow direction in Figures 1 to 3) or pulling it in the opposite direction (backward), the control unit 6 (see the block diagram in Figure 11) determines this as a trigger and sends current to the motor 32, thereby giving rotational motion to the wheel 3 and assisting the movement of the object to be transported 9 (forward and backward movement).

[0025] The transport assistance device 1 is preferably applied to a transport object 9, such as a stretcher 9 or a mobile bed, which is equipped with multiple (two or more) driven wheels and is used in hospitals and the like, and is particularly preferably applied to a stretcher 9.

[0026] Figures 1 to 3 show a stretcher 9 as an example of an object to be transported 9. The stretcher 9 to which the transport assistance device 1 is attached has a horizontal bed section 91 for placing a patient (not shown) in a lying position, which in Figure 1 etc. is installed with a cushioning mat 92 laid on it. Furthermore, it is possible to move in any direction by swivelable driven wheels 93 located at the four corners of the lower part of the bed section 91 (although only three driven wheels 93 are shown in Figure 1, there are actually four driven wheels 93).

[0027] Furthermore, railings (transfer boards) 94 are installed on both sides of the bed section 91 that constitutes the stretcher 9, which is the object to be transported 9. These railings 94 are rotatable around a pivot axis (not shown) that extends longitudinally (see Figure 1; the same applies hereafter) at both ends of the bed section 91. When moving a patient or other person to another location, the railings 94 can be lowered to act as a bridge to the bed section 91, and when transporting a patient or other person, the railings 94 can be raised to act as side rails to prevent the patient or other person from sliding or falling. The railings 94 can also be fixed horizontally and can be used as a so-called upper limb support.

[0028] As shown in Figure 1, the drive unit 2 constituting the transport assist device 1 is attached to a third support frame F3, which is arranged perpendicular to the longitudinal direction of the stretcher 9 (perpendicular to the first support frame F1 and the second support frame F2) between two support frames (first support frame F1 and second support frame F2) arranged in the longitudinal direction of the stretcher 9 at the lower part of the stretcher 9 with the above configuration (the lower part, which, when the transport assist device 1 is attached, refers to the part on which the wheel 3 can be made contact with the ground in the same way as the driven wheel 93; the same applies hereinafter). Furthermore, a control unit 7, which is a housing including a control unit 6, is attached to the first support frame F1.

[0029] As shown in Figure 2, when the pedal 21 is not pressed down, the wheel 3 that constitutes the drive unit 2 is in a raised position and does not make contact with the ground, and the motor 32 of the drive unit 2 is also not powered on. On the other hand, as shown in Figure 3, when the pedal 21 is pressed down, the wheel 3 is lowered and can make contact with the transport surface, and the motor 32 is also powered on.

[0030] Here, the transport assistance device 1 according to the present invention is A transport assist device 1 is attached to a transport object 9 equipped with multiple driven wheels 93, and is used to assist in the movement of the transport object 9, A wheel 3 is arranged in a row, one or more of them, with a common rotating shaft 31, and is capable of rotation. A motor 32 is connected to the wheel 3 with the aforementioned rotating shaft 31 in common, and is driven by the rotation of the rotating shaft 31 when current flows through it. A pedal 21 that lowers the wheel 3 to bring it into contact with the transport surface, A drive unit 2 is provided for attachment to the object to be transported 9, A rotation sensor 51 detects the rotation state of the wheel 3, A control unit 6 controls the drive of the motor 32, It is equipped with the following as its basic configuration. The individual components that make up this transport assistance device 1 will be described below.

[0031] (1) Drive unit 2: Figure 4 is a perspective view showing one aspect of the drive unit 2, Figures 5 and 6 are side views (viewed from the direction in which the wheel 3 is attached) showing one aspect of the drive unit 2, and Figures 7 and 8 are rear views (viewed from the opposite direction to the direction in which the pedal 21 is attached) showing one aspect of the drive unit 2. Figures 5 and 7 show the state in which the wheel 3 is raised without pressing down on the pedal 21, while Figures 4, 6, and 8 show the state in which the wheel 3 is lowered by pressing down on the pedal 21.

[0032] The wheels 3 that make up the drive unit 2 rotate and drive the transport assist device 1 and the object to be transported 9 (such as a stretcher 9) attached to the lower part of the transport assist device 1 in order to move it.

[0033] The wheel 3 is formed from a substantially disc-shaped member, and one or more wheels (two or more) are arranged side by side so that they are rotatable parallel to the direction of travel (the direction of the arrow in Figure 1, etc.), with the rotation axis 31 of the wheels 3 being perpendicular to the direction of travel, using a common rotation axis 31. In this embodiment, a configuration is shown in which a single wheel 3 is arranged so as to be rotatable parallel to the direction of travel.

[0034] As described above, since the wheels 3 are arranged in a single (one wheel 3 in this embodiment) or in multiples arranged in parallel, with each wheel 3 rotatable on a common rotation axis 31, the configuration is simpler and the transport assist device 1 is less expensive compared to transport assist devices 1 that use Mecanum wheels or omni wheels, which require multiple rotation axes and multiple wheels. There are no particular restrictions on the number of wheels 3, but it is generally preferable to have 1 to 3 wheels (arranged in parallel if there are multiple), however, to further simplify the configuration, it is especially preferable to have only one wheel 3.

[0035] Furthermore, as described above, the transport assist device 1 has the wheels 3 of the drive unit 2 arranged side by side, rotatable on a common rotation axis 31. Therefore, it only performs forward and backward (reverse direction to forward; the same applies hereinafter) movements through the rotational motion of the drive unit 2 or the wheels 3, and does not basically support movements other than these, such as turning or movements in the left / right (diagonal) direction.

[0036] In order for the object to be transported 9, such as a stretcher 9 to which the transport assist device 1 is attached, to perform movements other than forward and backward movement, such as turning or left / right (diagonal) movements, it is preferable to raise the pedal 21 of the drive unit 2 so that the wheel 3 of the drive unit 2 does not touch the ground, as shown in Figure 2, and perform the movement using the swivelable driven wheels 93 that are pre-installed on the stretcher 9. In this case, the power to the motor 32 of the drive unit 2 is not turned on, and the motor 32 is not driven to perform forward and backward movements using the wheel 3.

[0037] As shown in Figure 4, a pedal 21 is attached to the drive unit 2, and the vertical movement of the pedal 21 (up and down motion) is linked to the vertical movement of the wheel 3 (up and down motion). In other words, when the transport assist device 1 is not used, the pedal 21 is raised and the wheel 3 is not touching the ground (away from the ground), but by pressing down on the pedal 21, the wheel 3 lowers and touches the ground.

[0038] Furthermore, when the power switch 71, which is located in the control unit 7 (see Figures 11 and 12, etc.) including the control unit 6 described later, is turned ON, the transporter steps down on the pedal 21 (which causes the wheel 3 to touch the ground), and the motor 32 is powered on. In this embodiment, as shown in Figures 7 and 8, a position sensor 54 is provided on the pedal stand 27 that constitutes the drive unit 2. This position sensor 54 detects the position of a position member 29 located on the support stand 24 to which the wheel 3 is attached (to which the pivot axis A1 of the pivot member 23 to which the wheel 3 is attached is attached), thereby simulating that the wheel 3 has touched the transport surface, and the motor 32 is powered on.

[0039] The drive unit 2 is fixed to the lower part of the stretcher 9 by attaching a fixed frame 22, which has a roughly U-shaped cross-section and is formed above it, to a third support frame F3 that is located at the lower part of the stretcher 9.

[0040] The wheel 3, which constitutes the drive unit 2, rotates around the rotation axis 31 (the rotation axis 31 is the rotation axis of the motor 32, which is the drive source described later). The oscillating member 23, to which the rotation axis 31 of the wheel 3 is attached, is mounted to the drive unit 2 so as to be able to swing together with the wheel 3, with the oscillating axis A1, which is movable inside the spring housing cylinder 25 attached to the support stand 24 of the drive unit 2, as its axis.

[0041] Furthermore, an elastic oscillating spring 26 is attached with one end fixed to shaft A2 and the other end to shaft A3, assisting the oscillating motion of the wheel 3 and the oscillating member 23. The oscillating spring 26 also helps to press the wheel 3 against the conveying surface (ground) when the wheel 3 makes contact with the ground, enabling it to follow the conveying surface.

[0042] The pedal 21 is housed in the pedal stand 27 of the drive unit 2. The pedal stand 27 is integrated with the support stand 24 and its vertical movement is synchronized, and it moves up and down along a linear guide 28 that guides the movement of these components.

[0043] Specifically, by pressing down on the pedal 21, the support stand 24, which has an opening for mounting the wheel 3 and the swinging member 23 to accommodate the pedal stand 27 and the wheel 3, moves down along the linear guide 28, and the wheel 3 moves down as the pedal 21 is pressed down and makes contact with the transport surface.

[0044] Furthermore, to accommodate the link mechanism L for raising and lowering the pedal 21, the pedal stand 27, which has an open section for mounting the pedal 21, is fitted with two suspension springs S. These springs assist in easily raising the pedal stand 27 by providing initial tension when lifting the grounded wheel 3 from the transport surface. Additionally, as shown in Figure 4, attaching a damper D (also called a shock absorber) to the pedal stand 27 of the drive unit 2 is preferable because it has advantages such as mitigating vibration noise when the pedal stand 27 rises.

[0045] As mentioned above, when the transport assist device 1 is not in use, the pedal 21 is raised, and similarly the wheel 3 of the drive unit 2 is raised and not in contact with the transport surface. When the power switch 71 of the transport assist device (see Figure 12, etc., described later) is on (set to ON), the transporter (user) presses down on the pedal 21, causing the wheel 3 to lower and make contact with the transport surface, and at the same time the power to the motor 32 is turned on.

[0046] In this embodiment, the pedal stand 27 that houses the pedal 21 moves up and down in conjunction with the up and down movement of the pedal 21. Furthermore, the up and down movement of the pedal stand 27 and the up and down movement of the support stand 24 are linked, which causes the up and down movement of the wheel 3, which is attached to the support stand 24 (more precisely, the pivoting member 23 to which the pivoting shaft A1 is attached, to which the rotating shaft 31 is attached), to be linked.

[0047] In addition, when the pedal 21 is pressed down, the wheel 3 is lowered, and the power to the motor 32 is turned on. Here, the up and down movement of the pedal 21 and the up and down movement of the wheel 3 are linked, and the power to the motor 32 is turned off when they are raised and on when they are lowered, for example, as follows.

[0048] In other words, by pressing down on the pedal 21, the position sensor 54 detects the position of the support stand 24, which is the member to which the oscillating member 23 (oscillating shaft A1), which is the member to which the wheel 3 (or its rotation axis 31), is attached, and the motor 31 is powered on based on the detection by the position sensor 54.

[0049] In this case, the position sensor 54 also acts as a switch to turn the motor 31 on or off. Furthermore, the up and down movement of the pedal 21 is linked to the up and down movement of the support stand 24, which is the member to which the pivot axis A1 of the pivot member 23, the member to which the rotation axis 31 of the wheel 3 is attached, is attached. The position sensor 54 detects the position of the support stand 24 by simulating it as the position of the wheel 3 (hereinafter, "the member to which the rotation axis 31 of the wheel 3 is attached" may simply be referred to as "the member to which the wheel 3 is attached").

[0050] Next, an example of a mechanism for linking the up-and-down movement of the pedal 21 with the up-and-down movement of the wheel 3 will be described. Figures 9 and 10 show the internal structure of the pedal stand 27, including the linkage mechanism L. Here, Figure 9 shows the state before pressing the pedal 21 (up), and Figure 10 shows the state after pressing the pedal 21 (down).

[0051] As shown in Figure 9 and other figures, this embodiment employs a link mechanism L including a first link L1 and a second link L2, which are multiple (two or more) link members that move the wheel 3 up and down in conjunction with the up and down movement of the pedal 21. This link mechanism L is housed in the pedal stand 27 of the drive unit 2 (see Figure 4), and the up and down movement of the pedal 21 and the up and down movement of the wheel 3 are linked by the movement of the movable parts 42 connected to the ends L1E and L1F of the link mechanism L and the fixing of the fixed parts 41.

[0052] The behavior of the fixed part 41 and movable part 42 connected to the link mechanism L will now be explained. The fixed part 41 is the part that is fixed to the fixed frame 22, which is one of the components that make up the drive unit 2. The movable part 42 is the part that moves up and down in response to the up and down movement of the pedal 21 via the link mechanism L. The base 421 that makes up the movable part 42 is fixed to the pedal stand 27 that makes up the drive unit 2. The movable part 42 moves up and down in response to the up and down movement of the pedal 21, which in turn causes the pedal stand 27 to move up and down, and the wheel 3 to which the pedal stand 27 is connected moves up and down.

[0053] In this embodiment, the fixed portion 41 comprises a flat top surface portion 411 and a fixed portion body 412 that houses the movable portion body 422 (described later) so as to be vertically movable. The top surface portion 411 constituting the fixed portion 41 is fixed and integrated with the fixed frame 22, which is a fixed and immovable member of the drive unit 2, thereby being fixed to the fixed and immovable member of the drive unit 2.

[0054] In this embodiment, the movable part 42 comprises a base 421 and a movable part body 422 that is built inside the fixed part body 412 and moves up and down inside the fixed part body 412. The components of the movable part 42, including the base 421, are fixed and integrated with the pedal stand 27 and move in conjunction with the up and down movement of the pedal 21. Although the base 421 is depicted as a flat plate in Figures 9 and 10 for convenience, there is no problem in making the base 421 the shape of the pedal stand 27 itself.

[0055] Furthermore, the pedal stand 27 is connected to and integrated with the support stand 24, which is the component to which the wheel 3 is attached. Therefore, when the pedal 21 moves up and down, the base 421 that constitutes the movable part 42 moves up and down, and the pedal stand 27 also moves up and down. As described above, the up and down movement of the pedal stand 27 and the up and down movement of the support stand 24 are linked, and the up and down movement of the wheel 3, which is attached to the support stand 24 (more precisely, the rotating shaft 31 is attached to the oscillating member 23 attached to the support stand 24), is linked.

[0056] Thus, the movable part 42 is positioned on the member to which the pedal 21 is attached (pedal stand 27), and the up-and-down movement of the base 421 and the movable part body 422 that constitute the movable part 42 is linked to the up-and-down movement of the member to which the wheel 3 is attached (rocking member 23, support stand 24) and the wheel 3.

[0057] As shown in Figure 9, the pedal 21 is fixedly attached to one end L1E of the first link L1, which constitutes the link mechanism L, by a pedal mounting member 43. The first link L1 is V-shaped in plan view, and a first pivot point M1 is provided at the bent portion L1X where the rod-shaped first portion L11 and the rod-shaped second portion L12 intersect. This bent portion L1X and the sides flanking it, the first portion L11 and the second portion L12, rotate around this first pivot point M1.

[0058] The second link L2, which is another link constituting the link mechanism L, is a rod link, and the other end L1F of the first link L1 and one end L2E of the second link L2 are connected via a second support point M2. The top surface 411 constituting the fixed part 41 is connected to the other end L2F of the second link L2 via a third support point M3.

[0059] When the first link L1 rotates with the first pivot point M1 as the pivot point, the top surface 411 of the fixed part 41 connected via the second link L2 is fixed to the fixed frame 22 in this embodiment, while the movable part body 422 on which the first pivot point M1 is located moves up and down, and in accordance with this, the base 421 also moves up and down, and the pedal stand 27 also moves up and down.

[0060] Inside the fixed body 412, a pin P is positioned at the bottom of the top surface 411, and a tension spring T is positioned between the pin P and the first pivot point M1, expanding and contracting with the vertical movement of the movable part 42 (extending when the movable part 42 goes down and contracting when it goes up). A recess R is formed at the bottom of the fixed body 412, and the first pivot point M1 fits into this recess R, acting as a stopper to prevent the movable body 422 or the movable part 42 from rising. In addition, a pin-shaped restraint Y is provided on the first link L1, which also prevents the first link L1 from rotating indefinitely.

[0061] The following describes the movement of the pedal 21 (down to up in the following explanation) and the link mechanism L using Figures 9 and 10. First, by pressing down on the pedal 21 from the state shown in Figure 9, as shown in Figure 10, the end of the first part L11 of the first link L1 on which the pedal 21 is located (one end L1E) rotates downward around the first pivot point M1, and the second part L12 rotates, causing the end on which the second pivot point M2 is located (the other end L1F) to move upward in an arc towards the main body 412 of the fixed part.

[0062] The second link L2, which is connected to the second part L12 of the first link L1 by the second pivot M2, rotates in a direction toward the fixed part body 412 as the second pivot M2 moves. As shown in Figure 10, the second part L12 of the first link L1 and the second link L2 become almost straight via the connecting second pivot M2, and the link mechanism L becomes a braced state.

[0063] The fixed part 41, which consists of a top surface 411 and a fixed part body 412, is fixed because the top surface 411 is fixed to the fixed frame 22. Therefore, by the link mechanism L, when the pedal 21 is pressed down, the first pivot point M1 descends, and the movable part 42, which consists of a movable part body 422 and a base 421 on which the first pivot point M1 is located, also descends in conjunction with that movement.

[0064] In this embodiment, since the base 421 is attached to the pedal stand 27, when the base 421 is lowered, the pedal stand 27 also lowers in conjunction with its movement, and the support stand 24, which is linked to the movement of the pedal stand 27, also lowers, and the wheel 3 attached to the support stand 24 (the wheel 3 to which the rotating shaft 31 is attached to the rocking member 23 to which the rocking shaft A1 is attached to the support stand 24; the same applies hereinafter) also lowers.

[0065] Furthermore, since the first link L1 is equipped with a pin-shaped restraining part Y, the restraining part Y contacts the side surface of the movable part body 422, thereby preventing the movable part body 422 and the base 421 (movable part 42) from descending indefinitely.

[0066] Next, we will explain the movement of the link mechanism L when the pedal 21 is raised. Raising the pedal 21 from the state shown in Figure 10 results in the opposite movement to the one described above. As shown in Figure 9, the first part L11 of the first link L1 on which the pedal 21 is located rotates around the first pivot point M1, causing one end (one end L1E) to rise, while the second part L12 rotates, causing the end (the other end L1F) on which the second pivot point M2 is located to move away from the main body 412 in an arc.

[0067] Furthermore, the second link L2, which is connected to the second part L12 of the first link L1 by the second pivot M2, rotates away from the fixed part body 412 as the second pivot M2 moves. The second part L12 of the first link L1 and the second link L2 bend via the connecting second pivot M2, forming a roughly inverted "L" shape.

[0068] The fixed part 41, consisting of the top surface 411 and the fixed part body 412, is fixed because the top surface 411 is fixed to the fixed frame 22. When the pedal 21 is raised by the link mechanism L, the tensioned state of the link mechanism L (the state in which the second part L12 of the first link L1 and the second link L2 are approximately straightened via the connecting second pivot point M2) is released, and the first pivot point M1 rises due to the restoring force of the tension spring T, and the movable part 42, consisting of the movable part body 422 and the base 421 on which the first pivot point M1 is located, also rises in accordance with that movement.

[0069] In this embodiment, since the base 421 of the movable part 42 is attached to the pedal stand 27, when the base 421 rises, the pedal stand 27 also rises in conjunction with its movement, and the support stand 24, which is linked to the movement of the pedal stand 27, also rises, and the wheel 3 attached to the support stand 24 also rises.

[0070] Although the pin P located on the first link L1 is separated from the movable part body 422, the first pivot point M1 attached to the movable part body 422 fits into a recess R formed in the lower part of the fixed part body 412, thereby preventing the first pivot point M1 and the movable part body 422 from rising more than necessary.

[0071] As described above, the base 421 of the movable part 42 is fixed to the support stand 24. Therefore, as described above, the movement of the movable part body 422 and the base 421 is linked to the movement of the support stand 24, or the oscillating member 23 to which the rotation axis 31 of the wheel 3 is attached, and the wheel 3. As a result, when the pedal 21 moves up and down, the wheel 3 also moves up and down.

[0072] Furthermore, as shown in Figures 7 and 8, the drive unit 2 is equipped with a position sensor 54. In this embodiment, the position sensor 54 has a switch function and detects the position of the wheel 3 by detecting the position of the position member 29 which is located on the support stand 24 to which the wheel 3 is attached.

[0073] In this embodiment, the position member 29 is provided on the support stand 24, and the pedal stand 27 detects the position of the support stand 24 or the wheel 3 attached to the support stand 24 by detecting the position of the position member 29. The position sensor 54 detects that the wheel 3 is lowered by the pedal 21 and reaches a preset position (in this embodiment, the position where the wheel 3 makes contact with the transport surface), and then turns on the power to the motor 32.

[0074] As shown in Figures 7 and 9, when the pedal 21 is raised, the support stand 24 to which the wheel 3 is attached is not lowered, so the sensor part 541 of the position sensor 54 is separated from the position member 29 and does not detect the position member 29.

[0075] On the other hand, as shown in Figures 8 and 10, when the pedal 21 is lowered, the support stand 24 to which the wheel 3 is attached also lowers, and the sensor part 541 of the position sensor 54 comes into contact with the position member 29, thereby detecting the position member 29. This detection is equivalent to detecting that the wheel 3 has reached a preset position, that is, the position where the wheel 3 is in contact with the transport surface, and the switch on the position sensor 54 is turned on, which in turn turns on the power to the motor 32.

[0076] Regarding the relationship between wheel 3 and motor 32, the motor 32, which serves as the driving source, is connected to the center of wheel 3 by the motor 32's rotation axis 31 (as described later, the rotation axis 31 of motor 32 and wheel 3 are common), thereby driving and connecting wheel 3 so that it can rotate. In other words, by connecting the rotation axis 31 of motor 32 to the center of wheel 3, the rotational motion of the rotation axis 31 of motor 32 is transmitted to wheel 3, making wheel 3 rotatable. In this way, motor 32 is connected to wheel 3 with a common rotation axis 31, and when current flows, the rotation axis 31 rotates and drives the motor 32.

[0077] In this embodiment, the motor 32 is shown as a so-called in-wheel motor, with the motor 32 built into the wheel 3. By integrating the motor 32 into the wheel 3 as an in-wheel motor, the wheel 3 and the motor 32 can be compactly housed together.

[0078] In this embodiment, the drive unit 2 has only one wheel 3, as described above, and therefore only one motor. The motor 32 may be configured as, for example, a three-phase DC brushless motor.

[0079] The power supply between the motor 32 (in-wheel motor) built into the wheel 3 that constitutes the drive unit 2 and the control unit 7, which includes the control unit 6 described later, can be easily performed by attaching a connection part (not shown) at the end of a cord 33 extending from the side of the wheel 3 (near the rotation axis 31) to a connector 72 located on the side of the control unit 7.

[0080] It is preferable to use the motor 32 in combination with a motor driver 34 (DC motor driver) (see the block diagram in Figure 11, described later). The motor driver 34 is a circuit for efficiently and accurately controlling the motor 32, and when using the motor driver 34, the supply of voltage or current to the motor 32 is carried out via the motor driver 34.

[0081] The rotational control (including the direction of rotation) of the motor 32 is achieved by adjusting the voltage applied to the motor 32 and the current flowing through it, and this rotational control is controlled by the motor driver 34. In this embodiment, a conventionally known motor driver 34 can be used for control by the motor driver 34. The power supply for operating the motor driver 34 is provided by the battery 73 built into the control unit 7. The motor driver 34 is built into the control unit 7, which will be described later.

[0082] (2) Rotation sensor 51: Figure 11 is a block diagram showing the configuration of the transport assist device 9, including the control unit 6. As shown in Figure 11, the drive unit 2, which includes an in-wheel motor integrating the wheel 3 and motor 32, is connected to a rotation sensor 51. The rotation sensor 51 detects a signal corresponding to the rotation state of the wheel 3. In this embodiment, the rotation sensor 51 is a rotary encoder (hereinafter sometimes simply referred to as "encoder") which detects the rotation speed and direction (rotation state) of the wheel 3, and the encoder converts the rotation speed of the wheel 3 into a pulse speed (Hz). Here, a rotary encoder is a type of rotation sensor that converts the mechanical displacement amount of rotation into an electrical signal and processes this signal to detect position, speed, etc.

[0083] As a rotary switch for the rotary sensor (rotary encoder) 51, a rotation speed corresponding to a predetermined set count (for example, selecting a rotation speed from between 100 and 300 rpm corresponding to multiple set counts between 200 and 400) may be set. As an interrupt for the rotary sensor (rotary encoder) 51 (meaning that external force has been applied), for example, if a suitable number of interrupts occur from a stopped state, it may be detected that the stretcher 9 (object to be transported 9) has been pushed in the direction of travel, and the rotation direction of the motor 32 may also be detected. However, the functions of the rotary sensor (rotary encoder) 51 are not limited to processing such set counts and ranges.

[0084] In this embodiment, the rotation sensor 51 detects the rotation speed and direction (rotation state) of the wheel 3, and the encoder converts the rotation state of the wheel 3 into pulse speed (Hz) as a parameter. However, the parameter used to convert the rotation state detected by the rotation sensor 51 is not limited to pulse speed (Hz). For example, the parameter may be the number of pulses (Hz), etc.

[0085] In addition, as a sensor, this embodiment includes a rotary encoder (encoder) which is a rotation sensor 51, and a tilt sensor 52 which detects the inclination angle of the transport surface on which the wheel 3 is grounded and the transported object moves. The tilt sensor 52 is installed horizontally inside the control unit 7 and grasps the inclination state of the transport assist device 1 or the transported object 9, and uses this inclination state as the transport surface of the wheel 3 to detect the inclination angle of the transport surface.

[0086] These sensors are connected to the control unit 6, which will be described later, and transmit the signal obtained by converting the detected information (signal) to the control unit 6. The rotation sensor 51 (rotary encoder), which is a sensor, transmits to the control unit 6 based on a threshold value of pulse speed. The tilt sensor 52 also transmits to the control unit 6 whether the direction of the tilt (up or down) and the degree of the tilt (a numerical value obtained by parameterizing the tilt angle) exceed a reference value.

[0087] (3) Control Unit 6 (Controller): The control unit 6 (controller) controls the operation of the motor 32 of the drive unit 2 (in this embodiment, the in-wheel motor built into the wheel 3) by determining whether or not to supply current to drive the motor 32 based on signals communicated from sensors (such as the rotation sensor 51, tilt sensor 52 (and load sensor 53 described later)) that detect the force applied by the transporter (which acts as a trigger).

[0088] The control unit 6 is comprised of a control circuit (control board) housed in a predetermined enclosure (control unit 7 in this embodiment), which includes, for example, a CPU (Central Processing Unit) (not shown), memory, etc., is managed by pre-created software, and is controlled by the control circuit (control board). The control unit 6 controls the signal from the rotation sensor 51 (a signal obtained by converting the rotation speed into pulse speed (Hz)) to a pulse width.

[0089] Furthermore, in this embodiment, the control unit 6 controls the rotational motion (or the rotational motion of the wheel 3) of the motor 32 based on the signal communicated from the tilt sensor 52, by determining whether or not to supply current to the motor 32. As described above, the tilt sensor 52 is built into the control unit 7.

[0090] Figure 12 is a perspective view showing one aspect of the control unit 7, and Figure 13 is a front view showing another aspect of the control unit 7. Including Figure 11, the control unit 7 incorporates a control unit 6, and on the front, there is a power switch 71 and a battery charging port 74 which is a terminal for charging the battery 73. Between the power switch 71 and the battery charging port 74, there is an assist display panel 75 which displays the assist status of the transport assist device 1. On the side, there is a connector 72 for attaching a connection part (not shown) at the end of a cord 33 extending from the drive unit 2 (motor 32).

[0091] The control unit 7 has a built-in battery 73. By connecting the terminal at the end of the cord extending from the charger 76 (see block diagram in Figure 11) to the battery charging port 74 and turning on the power of the charger 76, the built-in battery 73 can be charged. The battery 73 serves as a power source for driving the transport assist device 1 according to the present invention, including the drive unit 2.

[0092] The control unit 7 has a mounting plate 77 on its top surface that includes a mounting portion 78 having a roughly inverted U-shaped cross-section. By combining and attaching the mounting portion 78 to the first support frame F1 which is disposed at the bottom of the stretcher 9 (transport device 9) as shown in Figure 1, the control unit 7 can be attached to the bottom of the stretcher 9.

[0093] (II) Regarding the processing performed by the control unit 6: Figures 14 to 16 are flowcharts showing an example of the processing performed by the control unit 6. Below, an example of the basic control of the drive unit 2 (such as the rotational motion of the motor 32 and wheel 3) by the control unit 6 when the transport assist device 1 according to this embodiment is attached to the lower part of the stretcher 9, which is the object to be transported 9, will be described.

[0094] First, let's explain using the flowchart in Figure 14. As shown in Figure 1, with the drive unit 2 and control unit 7 of the transport assist device 1 attached and fixed to the bottom of the stretcher 9, which is the object to be transported 9, the power switch 71 of the control unit 7 is turned ON. This turns on the power to the control unit 7, including the control unit 6 (Step 1 in Figure 14 (labeled "S1" in Figures 14 to 16. The same applies to "Step" in these figures below)).

[0095] In this state, as shown in Figure 2, the pedal 21 is not pressed down, the wheel 3 is in the raised position, the wheel 3 is not touching the ground, and the motor 32 is not powered on. On the other hand, when a transporter such as a nurse (who is also the user of the stretcher (object to be transported) 9 or the transport assistance device 1) presses down the pedal 21 of the drive unit 2 (step 2), as shown in Figure 3, the wheel 3 constituting the drive unit 2 is lowered and touches the transport surface, and the position sensor 54 detects the position of the position member 29, which is positioned to correspond to the wheel 3 touching the ground, and thus the motor 32 is powered on (step 3). Note that in any state, if the pedal 21 is raised, the motor 32 is powered off, and the state returns to step 1, where only the power switch 71 of the control unit 7 is turned on. Also, if the power switch 71 of the control unit 7 is turned off, the state returns to the "start" state shown in Figure 14.

[0096] As in step 3, when the power switch 71 of the transport assist device 1 is turned ON, and the motor 32 is powered on in the initial state (hereinafter sometimes simply referred to as the "initial state"), if the transporter applies a force to push the stretcher 9 in the direction of travel (step 4), the wheel 3 senses the force in the direction of travel and rotates in that direction (step 5), and the rotary encoder (encoder), which is the rotation sensor 51, detects the rotation of the wheel 3 and its direction, and converts the rotation speed into a pulse speed (Hz) (step 6). The rotation sensor 51 may also be configured to, for example, if the wheel 31 is pushed in the direction of travel from a stopped state, and there are, for example, several dozen interruptions, it may be configured to start operation as if the stretcher 9 has been pushed, and to detect the rotation direction of the motor 32.

[0097] The control unit 6, connected to the rotation sensor 51, determines whether the signal from the rotation sensor 51 reaches a preset pulse speed threshold. Specifically, the control unit 6 determines whether the signal from the rotation sensor 51 is equal to or greater than a preset pulse speed threshold (for example, a threshold of A (Hz), which can be set arbitrarily) (step 7).

[0098] (i) When the conveying surface on which wheel 3 makes contact is flat: In addition to cases where the control unit 6 determines that the value is above a threshold (when step 7 is "YES"; if it falls below the threshold, step 7 becomes "NO" and the system returns to step 6), the tilt sensor 52 also detects the tilt state of the transport surface in parallel (step 8. Specifically, the tilt angle θ of the transport surface is detected and converted into a predetermined parameter and quantified, but details will be described later). If the transport surface is flat (when step 9 is "YES", and as described in (iii) below, it is not an inclined surface), the control unit 6 instructs the battery 73 to supply a certain amount of current sufficient to drive the motor 32.

[0099] Thus, when the transport surface is flat (not an inclined surface as described in (iii) below), a certain amount of current flows from the battery 73 to the motor 32 (step 10), driving the motor 32's rotation axis to rotate in the forward direction (step 11). The wheel 3, whose center is connected to the rotation axis 31 of the motor 32, also rotates, assisting the stretcher 9 to move in the direction of travel. Here, "a certain amount of current" is the amount of current that causes the motor 32's rotation axis 31 to rotate and the wheel 3 of the transport assist device 1 to rotate, thereby moving the transported object 9, the stretcher 9, forward.

[0100] In this way, the control unit 6 drives the motor 32 by supplying a fixed amount of current to it via the battery 73, thereby rotating the wheel 3 which is connected to the rotation axis 31 of the motor 32 (which is also the rotation axis 31 of the wheel 3; the same applies hereafter). The rotation sensor 51 (encoder) sends a message to the control unit 6 based on a pulse speed threshold, and based on this message, the control unit 6 switches the current to the motor 32 on or off as described above. In other words, the control unit 6 switches the motor 32 on (or off) based on the message from the rotation sensor 51 (and the tilt sensor 52 described later).

[0101] Furthermore, if the transporter pulls the stretcher 9 in the opposite direction to the direction of travel (applies a pulling force), the control and behavior of the control unit 6, etc. are the same, only the direction differs, so the explanation is omitted. For example, in step 4 (S4) of Figure 14, if a force is applied to the stretcher 9 in the opposite direction to the direction of travel, the motor driver 34 causes the rotation of the motor 32's rotation axis 31 to be in the opposite direction to the forward direction, and the control unit 6, etc. performs the same control as described above.

[0102] (ii) When you want to decelerate while driving and when coasting: Next, we will explain using the flowchart in Figure 15. As described above, when the stretcher 9 (object to be transported 9) is driven and moving in the direction of travel (indicated by "X" in Figure 15 (and Figure 14)), if you want to decelerate the drive of the motor 32 of the drive unit 2 that drives the stretcher 9 (corresponding to the rotation of the wheel 3), the transporter applies a force pulling the object to be transported in the opposite direction of travel (step 12), which reduces the rotation speed of the wheel 3, and the rotary encoder, which is the rotation sensor 51, detects the decrease in the rotation speed of the wheel 3 (step 13).

[0103] The rotation sensor 51 detects the decrease in the rotation speed of the wheel 3 and the converted pulse speed. The pulse speed converted by the rotation sensor 51 also decreases, and when the pulse speed signal from the rotation sensor 51 falls below a predetermined threshold (e.g., A (Hz)) (if step 14 is "YES"), the current flowing to the motor 32 via the battery 73 is stopped (step 15). If the pulse speed does not fall below the predetermined threshold (if step 14 is "NO"), the system returns to state "X" in Figure 15 and repeats (the same applies to coasting as described below).

[0104] When the current flowing to motor 32 is stopped and no current flows to motor 32, the rotation speed of wheel 3 gradually decreases and it soon stops (step 16). In this case, if the transporter intends to stop stretcher 9, it can be stopped. On the other hand, if the transporter wants to move stretcher 9 forward again, it will return to the "initial state" described above.

[0105] Furthermore, if the transporter releases their grip on the stretcher 9 while it is moving in the direction of travel, etc., and it begins to coast (step 12), the wheels 32 or the stretcher 9 will also gradually decelerate, and the rotary encoder, which is the rotation sensor 51, will detect the decrease in the rotation speed of the wheels 3 and the converted pulse speed (step 13).

[0106] Furthermore, the pulse speed converted by the rotation sensor 51 also decreases, and when the pulse speed signal from the rotation sensor 51 falls below a predetermined threshold (for example, A (Hz)) (step 14 is "YES"), the current flowing to the motor 32 is stopped, the rotation speed of the wheel 3 gradually decreases, and it soon stops (steps 15 and 16). The stretcher 9 also soon stops, returning to the "initial state" described above.

[0107] Thus, when the transport assist device 1 enters a state of coasting during driven travel, it simply releases the current naturally (cutting off the power supply, leaving it in a free state), while the control unit 6 does not apply any control to brake the rotation speed of the motor 32 (such as applying a brake while driving the motor 32 by supplying current). Since the travel speed of the transport assist device 1 according to the present invention is approximately 1.0 to 1.5 m / s, if an emergency stop is desired, the transporter can easily stop the stretcher 9 on their own.

[0108] (iii) When the conveying surface on which wheel 3 makes contact is an inclined surface: The case where the transport surface is an inclined surface will be explained using the flowchart in Figure 16. The tilt sensor 52 detects the inclination angle θ of the transport surface (the inclination angle can be set arbitrarily (for example, it may be +10 to 20° if θ > 0, -10 to 20° if θ < 0, etc., but it is not limited to this), and this inclination angle is quantified as a predetermined parameter and detected. The same applies hereinafter) (step 8 in Figure 14). If the tilt sensor 52 detects that the transport surface is not flat based on the information of the inclination angle θ of the transport surface (when step 9 is "NO"), the processing performed by the control unit 6 is as follows (if step 9 is "YES", refer to (i) above).

[0109] First, if the incline is uphill (an uphill inclined surface), and the incline sensor 52 sends a signal (a numerical signal) to the control unit 6 indicating that the incline angle θ of the transport surface is greater than or equal to a predetermined angle θ1 (since it is uphill, θ1 > 0) (if step 17 is "YES"), the control unit 6 will send a current to the motor 32 via the battery 73 that is greater than the current that is sent when the transport surface is flat (the current that is sent when it is above a threshold) (step 18).

[0110] As the amount of current flowing to the motor 32 increases, the driving force of the motor 32 or the driving force of the wheel 2 also increases, causing acceleration. Therefore, even when the conveying surface is an uphill slope, it is possible to perform simple travel just as when the conveying surface is flat (Step 19 (the travel itself is the same as Step 10 in Figure 14)).

[0111] On the other hand, if the incline is a downhill slope (downward inclined surface) (step 17 is "NO"), if the incline sensor sends a signal (digitized signal) to the control unit 6 indicating that the incline angle θ of the transport surface is less than or equal to a predetermined angle θ2 (because it is a downhill slope, θ2 < 0) (if step 20 is "YES"), the control unit 6 activates a regenerative brake (not shown) incorporated into the motor 32 (step 21) to cause the wheel 3 to rotate in the opposite direction to the direction of travel (step 22), and soon returns to the "initial state" described above.

[0112] Due to the regenerative braking (not shown), a certain limit (brake) is applied to the driving force of the motor 32 or the driving force of the wheel 3, causing deceleration. Therefore, even when the transport surface is a downward slope, it can be easily driven in the same way as when the transport surface is flat.

[0113] Here, even on a downhill slope, the degree to which the regenerative brake (not shown) is applied, which is activated when the angle is "less than or equal to a predetermined angle θ2," remains constant. Furthermore, the degree to which the regenerative brake is applied is not increased further (stepwise control) simply because the inclination angle θ becomes smaller.

[0114] Furthermore, if the inclination angle θ of the transport surface exceeds a predetermined angle θ2 and falls below θ1 (θ2 < θ < θ1; where the upward direction is positive (+) and the downward direction is negative (-), and θ1 > 0, θ2 < 0), (when step 20 is "NO"), the inclination sensor 52 communicates its signal to the control unit 6, and the control unit 6 determines that "although it was determined in step 9 that the surface was not flat, ultimately the transport surface is considered flat and not inclined," and continues the behavior as if the transport surface were not inclined ("Z" in Figure 14 above).

[0115] Furthermore, the amount of current increased when the "predetermined angle θ1 or greater" is determined is constant, and the current is not further increased (stepwise control is not performed) simply because the inclination angle θ becomes larger. Also, if the inclination angle θ becomes smaller than the predetermined angle due to subsequent progress, including the uphill slope mentioned above, the system returns to point "Z" in Figure 14.

[0116] (III) Effects of the invention: As described above, the transport assist device 1 according to this embodiment can be driven by determining the force applied by the transporter at the start of movement through the control of the control unit 6, thus eliminating the need for an operating unit and providing good usability. In addition, since the power to the motor 32, which is the drive source, is turned on by the manual operation of lowering the pedal 21 to lower the wheel 3 to the transport surface, it is possible to prevent incorrect movement even if there is a malfunction in the control unit or other error. Furthermore, since the wheels 3 that constitute the drive unit 2 are arranged one or more in a rotatable state with a common rotation shaft 31, it has a simple configuration unlike Mecanum wheels and the like, which require the presence of multiple rotation shafts 31 and multiple wheels 3, resulting in a low-cost transport assist device 1.

[0117] (IV) Variations of the embodiment: It should be noted that the embodiments described above represent only one aspect of the present invention, and the present invention is not limited to the embodiments described above. It goes without saying that modifications and improvements within the scope of achieving the objectives and effects of the present invention are included in the scope of the present invention. Furthermore, the specific structure and shape used when implementing the present invention may be other structures and shapes, as long as they achieve the objectives and effects of the present invention. The present invention is not limited to the embodiments described above, and modifications and improvements within the scope of achieving the objectives of the present invention are included in the scope of the present invention.

[0118] For example, the transport assistance device 1 may be equipped with a pressure-sensitive conductive member as a load sensor 53 (see block diagram in Figure 11) that detects the weight loaded onto the transport object 9, such as the weight of a patient placed on the transport object 9, and the control unit 6 may determine, based on the signal from the load sensor 53, to supply a current amount to the motor 32 corresponding to the loaded weight (for example, the weight of a patient placed on the stretcher 9).

[0119] Here, "pressure-sensitive conductive material" refers to a material that exhibits insulating properties when not pressurized, but conductive properties when pressurized, and is preferably in sheet form. Examples of pressure-sensitive conductive materials include pressure-sensitive conductive rubber and pressure-sensitive conductive elastomer, which are formed by compounding conductive carbon particles, metal particles, or short fibers with a base material such as synthetic rubber or thermoplastic elastomer.

[0120] A pressure-sensitive conductive member becomes conductive when, for example, a load (pressure) is applied, conductive particles or short fibers in the base member come into contact with each other, forming a conductive path, which reduces the electrical resistance and thus makes the member conductive.

[0121] Here, in the context of pressure-sensitive conductive materials, "exhibiting conductivity" generally means that the volume resistivity is 1 × 10⁻⁶. 2It is preferable that the volume resistivity be Ω·cm or less, and particularly preferable that it be 1 × 10 Ω·cm or less, but it is not limited to this range. Furthermore, "exhibiting insulating properties" means, for example, that the volume resistivity is 1 × 10 7 It is preferable that it exceeds Ω·cm, and 1 × 10 10 While a value exceeding Ω·cm is particularly preferable, this is not necessarily limited to this range.

[0122] Furthermore, "volume resistivity" can be measured in accordance with the measurement methods for volume resistivity and surface resistivity of general insulating materials, or standard test methods for the properties of rubber (e.g., ASTM-D-257 or ASTM-D-991).

[0123] In the transport assistance device 1, for example, a pressure-sensitive conductive member that serves as a load sensor 53 is applied to a mat placed on the object to be transported, and the characteristic of the pressure-sensitive conductive member that its electrical resistance changes (decreases) when a load is applied due to the weight of the patient or other person being transported is used for load conversion.

[0124] Specifically, the pressure-sensitive conductive rubber load sensor 53 detects and transmits data (electrical resistance value), which is then converted from analog to digital (A / D) and transmitted wirelessly using Bluetooth (registered trademark) or the like to send a signal to the control unit 6 (control board). The control unit 6 then determines this signal and controls the driving force of the motor 32 by supplying a current amount appropriate to the patient's weight, for example, increasing the driving force of the motor 32 as the patient's weight increases.

[0125] Furthermore, if the load capacity is set to the weight of the patient placed on the transport object 9, such as the stretcher 9, the control unit 6 may divide the weight (load capacity) into stages and control the amount of current supplied to the motor 32 to increase in stages according to the divided load. The weight may be divided into stages such as 0 kg (no load), 30 kg, 60 kg, 100 kg, etc.

[0126] In the above-described embodiment, the control unit 6 made a determination based on thresholds such as the rotation sensor 51, the tilt sensor 52, and the control unit 6, using thresholds such as A(Hz) or higher, or the tilt angle θ being θ1 or higher when going up, or θ2 or lower when going down. However, the processing of the control unit 6 described above is just one example, and there is no problem in having the control unit 6 make a determination based on thresholds such as A(Hz) or tilt angle θ1 or lower, or tilt angle θ2 or lower. Furthermore, the processing of the control unit 6 can be appropriately determined within the range in which it determines whether or not to supply current to drive the motor 32 based on the signal communicated from the rotation sensor 51.

[0127] In the embodiment described above, the position sensor 54 detected the position of the support stand 24, which is the member to which the pivot axis A1 of the pivot member 23, the member to which the rotation axis 31 of the wheel 3 is attached, was assumed to be the position of the wheel 3. However, the position sensor 54 may also detect the position of the pivot member 23 to which the rotation axis 31 of the wheel 3 is attached, as an assumption of the position of the wheel 3, or it may detect the position of the wheel 3 itself.

[0128] In the embodiments described above, a stretcher 9 was used as an example of an object to be transported 9. However, the transport assist device 1 according to the present invention is not limited to a stretcher 9, but can be applied to conventionally known objects to be transported 9 such as mobile beds, trolleys, and transport carts. Furthermore, the specific structure and shape of the present invention may be other structures, etc., as long as they can achieve the objectives of the present invention. [Industrial applicability]

[0129] This invention has high industrial applicability as a device for assisting in the transport of objects such as stretchers. [Explanation of symbols]

[0130] 1... Conveying assistance device 2... Drive unit 21... Pedals 22... Fixed frame 23 …… Oscillating member 24... Support stand 25... Spring housing cylinder 26... Oscillating spring 27... Pedal stand 28... Linear guide 29 …… Positioning member 3... Wheel 31... Rotation axis 32... Motor 33... Code 34... Motor driver 41 …… Fixed part 411...Top section 412 …… Fixed part main body 42...Movable part 421... Pedestal 422 ……Movable part main body 43... Pedal mounting component 51... Rotation sensor 52... Tilt sensor 53... Load sensor 54... Position sensor (microswitch) 541... Sensor section 6. Control Unit 7. Control Unit 71... Power switch 72... Connector 73... Battery 74... Battery charging port 75... Assist display panel 76 …… Charger 77 …… Mounting plate 78... Mounting part 9. ... Object to be transported (stretcher) 91... Sleeping area 92 …… Matt 93... Driven wheels 94... Fence body (transfer board) A1... Oscillating axis A2,A3... Axis D... Damper (shock absorber) F1... First support frame F2... Second support frame F3... Third support frame L... Link mechanism L1... Link 1 L11... Part 1 L12... 2nd part L1E …… One end L1F …… The other end L1X ……Bent part L2... Second Link L2E …… One end L2F... The other end M1 …… First support point M2... Second fulcrum M3... Third support point P... Pin R... recess S... Suspension spring T... Tension spring Y... Stopping part

Claims

1. A transport assist device attached to a transport object equipped with multiple driven wheels, for assisting the movement of said transport object, A wheel is a system in which one or more wheels are arranged in a line, rotatable, with a common axis of rotation. A motor is connected to the wheel with a common rotating shaft, and is driven by the rotation of the rotating shaft when an electric current flows through it. A pedal that lowers the wheel to bring it into contact with the transport surface, It comprises a drive unit for being attached to the object to be transported, A rotation sensor for detecting the rotation state of the wheel, The system comprises a control unit for controlling the drive of the motor, By lowering the pedal, the motor is powered on. A transport assist device characterized in that the control unit determines whether or not to supply current to drive the motor based on a signal communicated from the rotation sensor.

2. The drive unit includes a linkage mechanism that comprises multiple linkage members, which is a mechanism for raising and lowering the wheel in conjunction with the up and down movement of the pedal, The system includes a position sensor for detecting the position of the wheel, The transport assist device according to claim 1, characterized in that when the position sensor detects that the pedal has been lowered and the wheel has been lowered to a preset position, the power to the motor is turned on.

3. The conveying assist device according to claim 1 or 2, characterized in that the wheel is pivotably mounted to the drive unit together with a member to which the rotation axis of the wheel is attached.

4. The up and down movement of the pedal is linked to the up and down movement of the member to which the wheel's rotation axis is attached, The transport assist device according to claim 2, characterized in that the position sensor detects the position of the member to which the rotation axis of the wheel is attached, or the position of the member to which the member is attached, by simulating it as the position of the wheel.

5. The transport assist device according to claim 1 or 2, characterized in that the control unit determines whether to supply current to drive the motor if the signal from the rotation sensor is above a preset threshold.

6. Furthermore, it is equipped with a tilt sensor that detects the inclination state of the conveying surface on which the object being conveyed moves, The transport assist device according to claim 5, characterized in that the control unit determines, based on the signal from the tilt sensor, that if the signal from the tilt sensor indicates that the transport surface is on an uphill slope and is equal to or greater than a preset tilt angle θ1 (θ1 > 0), it will supply the motor with a current that is greater than the current supplied when the tilt is equal to or greater than the threshold.

7. The transport assist device according to claim 6, characterized in that the control unit determines, based on the signal from the tilt sensor, that if the signal from the tilt sensor indicates that the transport surface is on a downhill slope and is less than or equal to a preset tilt angle θ2 (θ2 < 0), the regenerative brake provided by the motor is activated so that the wheel rotates in the opposite direction to the direction of travel.

8. The transport assist device according to claim 1 or 2, characterized in that the wheels are 1 to 3.

9. Furthermore, it is equipped with a load sensor that detects the weight loaded onto the object to be transported, The load sensor is a pressure-sensitive conductive member, The transport assist device according to claim 1 or 2, characterized in that the control unit determines, based on the signal from the load sensor, to supply a current to the motor in an amount corresponding to the weight being loaded.

10. The object to be transported is a stretcher, The transport assist device according to claim 1 or 2, characterized in that the drive unit is attached to the lower part of the stretcher.

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